from statistics import median, mean

# 使用：alias.function_name()
list_1 = [1, 2, 3, 4, 5]
list_2 = [1, 2, 3, 4, 5]
print(median(list_1))
print(mean(list_1))

print("=" * 50)
# import module_name as alias    给模块起别名
# 使用：alias.function_name()

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt

arr = np.array([1, 2, 3])
print(arr)

print("\n" + "=" * 50)
import os
import sys

# os 模块
print(os.getcwd())  # 当前目录
print(os.listdir('.'))  # 列出文件

# sys 模块
print(sys.version)  # Python版本
print(sys.path)  # 模块搜索路径